Re: [ATM] flex rocker azimuth stickiness

["John Sherman" <atmer@johnspics.com>]

Hi Rod,

>I am finding it difficult to get smooth azimuth motion.

One benefit of the flex rocker is that the pads are father from the AZ axis, 
which gives greater stability in the mount. It also reduces leverage, so the 
pads don't move as easily. It also exposes the pads to dirt. I clean the 
dirt with rough sandpaper, what we call 80 - 100 grit here in the USA. It's 
important to sand in the direction perpendicular to the motion the formica 
moves across the pads.

I think the best solution is to have three roller bearings and one Teflon 
pad riding on smooth laminate. I did this on a 17.5" and John Dobson himself 
told me "This is how a telescope is supposed to move!" On my 22" I tried 
four skateboard wheels, and a carpet pad for braking. The pad has a bolt for 
adjustment. It doesn't work as well as one Teflon pad and the rest hard ball 
bearings. One problem with the hard roller bearings is that they can dent 
the formica if it has a soft spot in the wood under it. That's why I went 
with the hard skateboard wheels, but they are a tad squishy, which is 
noticeable at the eyepiece.

I hope this helps,

John






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